Some client applications fail to negotiate SSL (error 80090331)


When trying to connect to a mail service over SSL it fails, with an error which indicates SSL negotiation failed. The service Debug logs indicate the error code 80090331, along with notes saying the SSL handshaking failed.


This can happen if the client connecting to the server does not support a protocol that the server is allowing. For instance, you may be trying to use a client application that supports SSLv2, but the server is only allowing SSLv3 or TLSv1. If your client is an older application this may be the case. You are able to check the supported server protocols and ciphers by using a tool such as SSL Diagnos, which can be found at:

If you are trying to determine what protocols the client supports, then Wireshark would be useful:



Upgrading the client application to support the same protocols of the server is the recommended solution. Downgrading the allowed server protocols is not recommended for security reasons. The MailEnable software will use the defaults of the server, so changes to the Windows settings, such as changing the allowed protocols, will be reflected in the mail services.


Class:INF: Product Information
Revised:Wednesday, May 4, 2016